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SSB demod: AGC step down

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This commit is contained in:
f4exb 2017-07-26 08:39:20 +02:00
parent 8452985061
commit da6b60d48c
2 changed files with 57 additions and 20 deletions
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55
sdrbase/dsp/agc.cpp
View File

@ -5,6 +5,7 @@
* Author: f4exb * Author: f4exb
*/ */
#include <algorithm>
#include "dsp/agc.h" #include "dsp/agc.h"
#include "util/smootherstep.h" #include "util/smootherstep.h"
@ -48,13 +49,21 @@ MagSquaredAGC::MagSquaredAGC(int historySize, double R, double threshold) :
m_magsq(0.0), m_magsq(0.0),
m_threshold(threshold), m_threshold(threshold),
m_gate(0), m_gate(0),
m_stepCounter(0), m_stepLength(std::min(2400, historySize/2)),
m_stepUpCounter(0),
m_stepDownCounter(0),
m_gateCounter(0) m_gateCounter(0)
{} {}
MagSquaredAGC::~MagSquaredAGC() MagSquaredAGC::~MagSquaredAGC()
{} {}
void MagSquaredAGC::resize(int historySize, Real R)
{
m_stepLength = std::min(2400, historySize/2);
AGC::resize(historySize, R);
}
void MagSquaredAGC::feed(Complex& ci) void MagSquaredAGC::feed(Complex& ci)
{ {
m_magsq = ci.real()*ci.real() + ci.imag()*ci.imag(); m_magsq = ci.real()*ci.real() + ci.imag()*ci.imag();
@ -91,16 +100,23 @@ double MagSquaredAGC::feedAndGetValue(const Complex& ci)
if (m_count < m_moving_average.historySize()) if (m_count < m_moving_average.historySize())
{ {
if (m_stepCounter < 2400) { m_stepDownCounter = m_stepLength;
m_stepCounter++;
if (m_stepUpCounter < m_stepLength) {
m_stepUpCounter++;
} }
return m_u0 * StepFunctions::smootherstep(m_stepCounter/2400.0); return m_u0 * StepFunctions::smootherstep(m_stepUpCounter/m_stepLength);
} }
else else
{ {
m_stepCounter = 0; m_stepUpCounter = 0;
return 0.0;
if (m_stepDownCounter > 0) {
m_stepDownCounter--;
}
return m_u0 * StepFunctions::smootherstep(m_stepDownCounter/m_stepLength);
} }
//return (m_count < m_moving_average.historySize()) ? m_u0 : 0.0; //return (m_count < m_moving_average.historySize()) ? m_u0 : 0.0;
@ -116,13 +132,21 @@ MagAGC::MagAGC(int historySize, double R, double threshold) :
m_magsq(0.0), m_magsq(0.0),
m_threshold(threshold), m_threshold(threshold),
m_gate(0), m_gate(0),
m_stepCounter(0), m_stepLength(std::min(2400, historySize/2)),
m_stepUpCounter(0),
m_stepDownCounter(0),
m_gateCounter(0) m_gateCounter(0)
{} {}
MagAGC::~MagAGC() MagAGC::~MagAGC()
{} {}
void MagAGC::resize(int historySize, Real R)
{
m_stepLength = std::min(2400, historySize/2);
AGC::resize(historySize, R);
}
void MagAGC::feed(Complex& ci) void MagAGC::feed(Complex& ci)
{ {
m_magsq = ci.real()*ci.real() + ci.imag()*ci.imag(); m_magsq = ci.real()*ci.real() + ci.imag()*ci.imag();
@ -159,16 +183,23 @@ double MagAGC::feedAndGetValue(const Complex& ci)
if (m_count < m_moving_average.historySize()) if (m_count < m_moving_average.historySize())
{ {
if (m_stepCounter < 480) { m_stepDownCounter = m_stepLength;
m_stepCounter++;
if (m_stepUpCounter < m_stepLength) {
m_stepUpCounter++;
} }
return m_u0 * StepFunctions::smootherstep(m_stepCounter/480.0); return m_u0 * StepFunctions::smootherstep(m_stepUpCounter/m_stepLength);
} }
else else
{ {
m_stepCounter = 0; m_stepUpCounter = 0;
return 0.0;
if (m_stepDownCounter > 0) {
m_stepDownCounter--;
}
return m_u0 * StepFunctions::smootherstep(m_stepDownCounter/m_stepLength);
} }
//return (m_count < m_moving_average.historySize()) ? m_u0 : 0.0; //return (m_count < m_moving_average.historySize()) ? m_u0 : 0.0;

22
sdrbase/dsp/agc.h
View File

@ -34,6 +34,7 @@ class MagSquaredAGC : public AGC
public: public:
MagSquaredAGC(int historySize, double R, double threshold); MagSquaredAGC(int historySize, double R, double threshold);
virtual ~MagSquaredAGC(); virtual ~MagSquaredAGC();
void resize(int historySize, Real R);
virtual void feed(Complex& ci); virtual void feed(Complex& ci);
double feedAndGetValue(const Complex& ci); double feedAndGetValue(const Complex& ci);
double getMagSq() const { return m_magsq; } double getMagSq() const { return m_magsq; }
@ -41,10 +42,12 @@ public:
void setGate(int gate) { m_gate = gate; } void setGate(int gate) { m_gate = gate; }
private: private:
double m_magsq; double m_magsq;
double m_threshold; //!< squelch on magsq average with transition from +3dB double m_threshold; //!< squelch on magsq average
int m_gate; int m_gate; //!< power threshold gate in number of samples
int m_stepCounter; int m_stepLength; //!< transition step length in number of samples
int m_gateCounter; int m_stepUpCounter; //!< step up transition samples counter
int m_stepDownCounter; //!< step down transition samples counter
int m_gateCounter; //!< threshold gate samples counter
}; };
class MagAGC : public AGC class MagAGC : public AGC
@ -52,6 +55,7 @@ class MagAGC : public AGC
public: public:
MagAGC(int historySize, double R, double threshold); MagAGC(int historySize, double R, double threshold);
virtual ~MagAGC(); virtual ~MagAGC();
void resize(int historySize, Real R);
virtual void feed(Complex& ci); virtual void feed(Complex& ci);
double feedAndGetValue(const Complex& ci); double feedAndGetValue(const Complex& ci);
Real getMagSq() const { return m_magsq; } Real getMagSq() const { return m_magsq; }
@ -59,10 +63,12 @@ public:
void setGate(int gate) { m_gate = gate; } void setGate(int gate) { m_gate = gate; }
private: private:
double m_magsq; double m_magsq;
double m_threshold; //!< squelch on magsq average double m_threshold; //!< squelch on magsq average
int m_gate; int m_gate; //!< power threshold gate in number of samples
int m_stepCounter; int m_stepLength; //!< transition step length in number of samples
int m_gateCounter; int m_stepUpCounter; //!< step up transition samples counter
int m_stepDownCounter; //!< step down transition samples counter
int m_gateCounter; //!< threshold gate samples counter
}; };
class AlphaAGC : public AGC class AlphaAGC : public AGC